/*
YUI 3.13.0 (build 508226d)
Copyright 2013 Yahoo! Inc. All rights reserved.
Licensed under the BSD License.
http://yuilibrary.com/license/
*/

YUI.add('uploader-queue', function (Y, NAME) {

/**
* The class manages a queue of files that should be uploaded to the server.
* It initializes the required number of uploads, tracks them as they progress,
* and automatically advances to the next upload when a preceding one has completed.
* @module uploader-queue
*/



/**
* This class manages a queue of files to be uploaded to the server.
* @class Uploader.Queue
* @extends Base
* @constructor
*/
var UploaderQueue = function() {
    this.queuedFiles = [];
    this.uploadRetries = {};
    this.numberOfUploads = 0;
    this.currentUploadedByteValues = {};
    this.currentFiles = {};
    this.totalBytesUploaded = 0;
    this.totalBytes = 0;

    UploaderQueue.superclass.constructor.apply(this, arguments);
};


Y.extend(UploaderQueue, Y.Base, {

    /**
    * Stored value of the current queue state
    * @property _currentState
    * @type {String}
    * @protected
    * @default UploaderQueue.STOPPED
    */
    _currentState: UploaderQueue.STOPPED,

    /**
    * Construction logic executed during UploaderQueue instantiation.
    *
    * @method initializer
    * @protected
    */
    initializer : function () {},

    /**
    * Handles and retransmits upload start event.
    *
    * @method _uploadStartHandler
    * @param event The event dispatched during the upload process.
    * @private
    */
    _uploadStartHandler : function (event) {
        var updatedEvent = event;
        updatedEvent.file = event.target;
        updatedEvent.originEvent = event;

        this.fire("uploadstart", updatedEvent);
    },

    /**
    * Handles and retransmits upload error event.
    *
    * @method _uploadErrorHandler
    * @param event The event dispatched during the upload process.
    * @private
    */
    _uploadErrorHandler : function (event) {
        var errorAction = this.get("errorAction"),
            updatedEvent = event,
            fileid,
            retries;

        updatedEvent.file = event.target;
        updatedEvent.originEvent = event;

        this.numberOfUploads-=1;
        delete this.currentFiles[event.target.get("id")];
        this._detachFileEvents(event.target);

        event.target.cancelUpload();

        if (errorAction === UploaderQueue.STOP) {
            this.pauseUpload();
        }

        else if (errorAction === UploaderQueue.RESTART_ASAP) {
            fileid = event.target.get("id");
            retries = this.uploadRetries[fileid] || 0;

            if (retries < this.get("retryCount")) {
                this.uploadRetries[fileid] = retries + 1;
                this.addToQueueTop(event.target);
            }
            this._startNextFile();
        }
        else if (errorAction === UploaderQueue.RESTART_AFTER) {
            fileid = event.target.get("id");
            retries = this.uploadRetries[fileid] || 0;

            if (retries < this.get("retryCount")) {
                this.uploadRetries[fileid] = retries + 1;
                this.addToQueueBottom(event.target);
            }
            this._startNextFile();
        }

        this.fire("uploaderror", updatedEvent);
    },

    /**
    * Launches the upload of the next file in the queue.
    *
    * @method _startNextFile
    * @private
    */
    _startNextFile : function () {
        if (this.queuedFiles.length > 0) {
            var currentFile = this.queuedFiles.shift(),
                fileId = currentFile.get("id"),
                parameters = this.get("perFileParameters"),
                fileParameters = parameters.hasOwnProperty(fileId) ? parameters[fileId] : parameters;

            this.currentUploadedByteValues[fileId] = 0;

            currentFile.on("uploadstart", this._uploadStartHandler, this);
            currentFile.on("uploadprogress", this._uploadProgressHandler, this);
            currentFile.on("uploadcomplete", this._uploadCompleteHandler, this);
            currentFile.on("uploaderror", this._uploadErrorHandler, this);
            currentFile.on("uploadcancel", this._uploadCancelHandler, this);

            currentFile.set("xhrHeaders", this.get("uploadHeaders"));
            currentFile.set("xhrWithCredentials", this.get("withCredentials"));

            currentFile.startUpload(this.get("uploadURL"), fileParameters, this.get("fileFieldName"));

            this._registerUpload(currentFile);
        }
    },

    /**
    * Register a new upload process.
    *
    * @method _registerUpload
    * @private
    */
    _registerUpload : function (file) {
        this.numberOfUploads += 1;
        this.currentFiles[file.get("id")] = file;
    },

    /**
    * Unregisters a new upload process.
    *
    * @method _unregisterUpload
    * @private
    */
    _unregisterUpload : function (file) {
        if (this.numberOfUploads > 0) {
            this.numberOfUploads -= 1;
        }

        delete this.currentFiles[file.get("id")];
        delete this.uploadRetries[file.get("id")];

        this._detachFileEvents(file);
    },

    _detachFileEvents : function (file) {
        file.detach("uploadstart", this._uploadStartHandler);
        file.detach("uploadprogress", this._uploadProgressHandler);
        file.detach("uploadcomplete", this._uploadCompleteHandler);
        file.detach("uploaderror", this._uploadErrorHandler);
        file.detach("uploadcancel", this._uploadCancelHandler);
    },

    /**
    * Handles and retransmits upload complete event.
    *
    * @method _uploadCompleteHandler
    * @param event The event dispatched during the upload process.
    * @private
    */
    _uploadCompleteHandler : function (event) {

        this._unregisterUpload(event.target);

        this.totalBytesUploaded += event.target.get("size");
        delete this.currentUploadedByteValues[event.target.get("id")];


        if (this.queuedFiles.length > 0 && this._currentState === UploaderQueue.UPLOADING) {
            this._startNextFile();
        }

        var updatedEvent = event,
            uploadedTotal = this.totalBytesUploaded,
            percentLoaded = Math.min(100, Math.round(10000*uploadedTotal/this.totalBytes) / 100);

        updatedEvent.file = event.target;
        updatedEvent.originEvent = event;

        Y.each(this.currentUploadedByteValues, function (value) {
            uploadedTotal += value;
        });

        this.fire("totaluploadprogress", {
            bytesLoaded: uploadedTotal,
            bytesTotal: this.totalBytes,
            percentLoaded: percentLoaded
        });

        this.fire("uploadcomplete", updatedEvent);

        if (this.queuedFiles.length === 0 && this.numberOfUploads <= 0) {
            this.fire("alluploadscomplete");
            this._currentState = UploaderQueue.STOPPED;
        }
    },

    /**
    * Handles and retransmits upload cancel event.
    *
    * @method _uploadCancelHandler
    * @param event The event dispatched during the upload process.
    * @private
    */
    _uploadCancelHandler : function (event) {

        var updatedEvent = event;
        updatedEvent.originEvent = event;
        updatedEvent.file = event.target;

        this.fire("uploadcancel", updatedEvent);
    },



    /**
    * Handles and retransmits upload progress event.
    *
    * @method _uploadProgressHandler
    * @param event The event dispatched during the upload process.
    * @private
    */
    _uploadProgressHandler : function (event) {

        this.currentUploadedByteValues[event.target.get("id")] = event.bytesLoaded;

        var updatedEvent = event,
            uploadedTotal = this.totalBytesUploaded,
            percentLoaded = Math.min(100, Math.round(10000*uploadedTotal/this.totalBytes) / 100);

        updatedEvent.originEvent = event;
        updatedEvent.file = event.target;

        this.fire("uploadprogress", updatedEvent);

        Y.each(this.currentUploadedByteValues, function (value) {
            uploadedTotal += value;
        });

        this.fire("totaluploadprogress", {
            bytesLoaded: uploadedTotal,
            bytesTotal: this.totalBytes,
            percentLoaded: percentLoaded
        });
    },

    /**
    * Starts uploading the queued up file list.
    *
    * @method startUpload
    */
    startUpload: function() {
        this.queuedFiles = this.get("fileList").slice(0);
        this.numberOfUploads = 0;
        this.currentUploadedByteValues = {};
        this.currentFiles = {};
        this.totalBytesUploaded = 0;

        this._currentState = UploaderQueue.UPLOADING;

        while (this.numberOfUploads < this.get("simUploads") && this.queuedFiles.length > 0) {
            this._startNextFile();
        }
    },

    /**
    * Pauses the upload process. The ongoing file uploads
    * will complete after this method is called, but no
    * new ones will be launched.
    *
    * @method pauseUpload
    */
    pauseUpload: function () {
        this._currentState = UploaderQueue.STOPPED;
    },

    /**
    * Restarts a paused upload process.
    *
    * @method restartUpload
    */
    restartUpload: function () {
        this._currentState = UploaderQueue.UPLOADING;
        while (this.numberOfUploads < this.get("simUploads")) {
             this._startNextFile();
        }
    },

    /**
    * If a particular file is stuck in an ongoing upload without
    * any progress events, this method allows to force its reupload
    * by cancelling its upload and immediately relaunching it.
    *
    * @method forceReupload
    * @param file {Y.File} The file to force reupload on.
    */
    forceReupload : function (file) {
        var id = file.get("id");
        if (this.currentFiles.hasOwnProperty(id)) {
            file.cancelUpload();
            this._unregisterUpload(file);
            this.addToQueueTop(file);
            this._startNextFile();
        }
    },

    /**
    * Add a new file to the top of the queue (the upload will be
    * launched as soon as the current number of uploading files
    * drops below the maximum permissible value).
    *
    * @method addToQueueTop
    * @param file {Y.File} The file to add to the top of the queue.
    */
    addToQueueTop: function (file) {
            this.queuedFiles.unshift(file);
    },

    /**
    * Add a new file to the bottom of the queue (the upload will be
    * launched after all the other queued files are uploaded.)
    *
    * @method addToQueueBottom
    * @param file {Y.File} The file to add to the bottom of the queue.
    */
    addToQueueBottom: function (file) {
            this.queuedFiles.push(file);
    },

    /**
    * Cancels a specific file's upload. If no argument is passed,
    * all ongoing uploads are cancelled and the upload process is
    * stopped.
    *
    * @method cancelUpload
    * @param file {Y.File} An optional parameter - the file whose upload
    * should be cancelled.
    */
    cancelUpload: function (file) {
        var id,
            i,
            fid;

        if (file) {
            id = file.get("id");

            if (this.currentFiles[id]) {
                this.currentFiles[id].cancelUpload();
                this._unregisterUpload(this.currentFiles[id]);
                if (this._currentState === UploaderQueue.UPLOADING) {
                    this._startNextFile();
                }
            }
            else {
                for (i = 0, len = this.queuedFiles.length; i < len; i++) {
                    if (this.queuedFiles[i].get("id") === id) {
                        this.queuedFiles.splice(i, 1);
                        break;
                    }
                }
            }
        }
        else {
            for (fid in this.currentFiles) {
                this.currentFiles[fid].cancelUpload();
                this._unregisterUpload(this.currentFiles[fid]);
            }

            this.currentUploadedByteValues = {};
            this.currentFiles = {};
            this.totalBytesUploaded = 0;
            this.fire("alluploadscancelled");
            this._currentState = UploaderQueue.STOPPED;
        }
    }
}, {
    /**
    * Static constant for the value of the `errorAction` attribute:
    * prescribes the queue to continue uploading files in case of
    * an error.
    * @property CONTINUE
    * @readOnly
    * @type {String}
    * @static
    */
    CONTINUE: "continue",

    /**
    * Static constant for the value of the `errorAction` attribute:
    * prescribes the queue to stop uploading files in case of
    * an error.
    * @property STOP
    * @readOnly
    * @type {String}
    * @static
    */
    STOP: "stop",

    /**
    * Static constant for the value of the `errorAction` attribute:
    * prescribes the queue to restart a file upload immediately in case of
    * an error.
    * @property RESTART_ASAP
    * @readOnly
    * @type {String}
    * @static
    */
    RESTART_ASAP: "restartasap",

    /**
    * Static constant for the value of the `errorAction` attribute:
    * prescribes the queue to restart an errored out file upload after
    * other files have finished uploading.
    * @property RESTART_AFTER
    * @readOnly
    * @type {String}
    * @static
    */
    RESTART_AFTER: "restartafter",

    /**
    * Static constant for the value of the `_currentState` property:
    * implies that the queue is currently not uploading files.
    * @property STOPPED
    * @readOnly
    * @type {String}
    * @static
    */
    STOPPED: "stopped",

    /**
    * Static constant for the value of the `_currentState` property:
    * implies that the queue is currently uploading files.
    * @property UPLOADING
    * @readOnly
    * @type {String}
    * @static
    */
    UPLOADING: "uploading",

    /**
    * The identity of the class.
    *
    * @property NAME
    * @type String
    * @default 'uploaderqueue'
    * @readOnly
    * @protected
    * @static
    */
    NAME: 'uploaderqueue',

    /**
    * Static property used to define the default attribute configuration of
    * the class.
    *
    * @property ATTRS
    * @type {Object}
    * @protected
    * @static
    */
    ATTRS: {

        /**
        * Maximum number of simultaneous uploads; must be in the
        * range between 1 and 5. The value of `2` is default. It
        * is recommended that this value does not exceed 3.
        * @attribute simUploads
        * @type Number
        * @default 2
        */
         simUploads: {
                 value: 2,
                 validator: function (val) {
                         return (val >= 1 && val <= 5);
                 }
         },

        /**
        * The action to take in case of error. The valid values for this attribute are:
        * `Y.Uploader.Queue.CONTINUE` (the upload process should continue on other files,
        * ignoring the error), `Y.Uploader.Queue.STOP` (the upload process
        * should stop completely), `Y.Uploader.Queue.RESTART_ASAP` (the upload
        * should restart immediately on the errored out file and continue as planned), or
        * Y.Uploader.Queue.RESTART_AFTER (the upload of the errored out file should restart
        * after all other files have uploaded)
        * @attribute errorAction
        * @type String
        * @default Y.Uploader.Queue.CONTINUE
        */
        errorAction: {
            value: "continue",
                validator: function (val) {
                return (
                    val === UploaderQueue.CONTINUE ||
                    val === UploaderQueue.STOP ||
                    val === UploaderQueue.RESTART_ASAP ||
                    val === UploaderQueue.RESTART_AFTER
                );
            }
        },

        /**
        * The total number of bytes that has been uploaded.
        * @attribute bytesUploaded
        * @type Number
        */
        bytesUploaded: {
            readOnly: true,
            value: 0
        },

        /**
        * The total number of bytes in the queue.
        * @attribute bytesTotal
        * @type Number
        */
        bytesTotal: {
            readOnly: true,
            value: 0
        },

        /**
        * The queue file list. This file list should only be modified
        * before the upload has been started; modifying it after starting
        * the upload has no effect, and `addToQueueTop` or `addToQueueBottom` methods
        * should be used instead.
        * @attribute fileList
        * @type Array
        */
        fileList: {
            value: [],
            lazyAdd: false,
            setter: function (val) {
                var newValue = val;
                Y.Array.each(newValue, function (value) {
                    this.totalBytes += value.get("size");
                }, this);

                return val;
            }
        },

        /**
        * A String specifying what should be the POST field name for the file
        * content in the upload request.
        *
        * @attribute fileFieldName
        * @type {String}
        * @default Filedata
        */
        fileFieldName: {
            value: "Filedata"
        },

        /**
        * The URL to POST the file upload requests to.
        *
        * @attribute uploadURL
        * @type {String}
        * @default ""
        */
        uploadURL: {
            value: ""
        },

        /**
        * Additional HTTP headers that should be included
        * in the upload request. Due to Flash Player security
        * restrictions, this attribute is only honored in the
        * HTML5 Uploader.
        *
        * @attribute uploadHeaders
        * @type {Object}
        * @default {}
        */
        uploadHeaders: {
            value: {}
        },

        /**
        * A Boolean that specifies whether the file should be
        * uploaded with the appropriate user credentials for the
        * domain. Due to Flash Player security restrictions, this
        * attribute is only honored in the HTML5 Uploader.
        *
        * @attribute withCredentials
        * @type {Boolean}
        * @default true
        */
        withCredentials: {
            value: true
        },


        /**
        * An object, keyed by `fileId`, containing sets of key-value pairs
        * that should be passed as POST variables along with each corresponding
        * file.
        *
        * @attribute perFileParameters
        * @type {Object}
        * @default {}
        */
        perFileParameters: {
            value: {}
        },

        /**
        * The number of times to try re-uploading a file that failed to upload before
        * cancelling its upload.
        *
        * @attribute retryCount
        * @type {Number}
        * @default 3
        */
        retryCount: {
            value: 3
        }

    }
});


Y.namespace('Uploader');
Y.Uploader.Queue = UploaderQueue;


}, '3.13.0', {"requires": ["base"]});
